Former commanding general of Walter Reed Army Medical Center Army Major Gen. George Weightman testifies before a House Oversight and Government Reform Committee hearing on the care and conditions of wounded soldiers at Walter Reed, in Washington at the Walter Reed Army Medical Center on March 5, 2007. (UPI Photo/Kevin Dietsch)

Major Walter Reed, M.D., (September 13, 1851 – November 22, 1902) was a U.S. Army physician who in 1900 led the team that postulated and confirmed the theory that yellow fever is transmitted by a particular mosquito species, rather than by direct contact. This insight gave impetus to the new fields of epidemiology and biomedicine, and most immediately allowed the resumption and completion of work on the Panama Canal (1904–1914) by the United States. Reed followed work started by Carlos Finlay and directed by George Miller Sternberg ("first U.S. bacteriologist").

After two year-long classes at the University of Virginia, Reed completed the M.D. degree in 1869, two months before he turned 18 (he was the youngest then, and is still today the youngest student of the University of Virginia to receive an MD degree). He then enrolled at the New York University's Bellevue Hospital Medical College in Manhattan, New York, where he obtained a second M.D. in 1870. After interning at several New York City hospitals, he worked for the New York Board of Health until 1875. He married Emilie (born Emily) Lawrence on April 26, 1876 and took her West with him. Later, Emilie would give birth to a son and a daughter and the couple would adopt a Native American girl while posted in frontier camps.

United Press International is a leading provider of news, photos and information to millions of readers around the globe via UPI.com and its licensing services.

With a history of reliable reporting dating back to 1907, today's UPI is a credible source for the most important stories of the day, continually updated - a one-stop site for U.S. and world news, as well as entertainment, trends, science, health and stunning photography. UPI also provides insightful reports on key topics of geopolitical importance, including energy and security.

A Spanish version of the site reaches millions of readers in Latin America and beyond.

UPI was founded in 1907 by E.W. Scripps as the United Press (UP). It became known as UPI after a merger with the International News Service in 1958, which was founded in 1909 by William Randolph Hearst. Today, UPI is owned by News World Communications.